4g63 Block Vent

[BogusSVO]

4G63 Block Vent

I have read a few threads on adding a block vent to the 4g63.
I know this not a new idea, and others have had done it before.
I also know that there is a kit so a block vent can be added in at the rear balance shaft timing passage.
Some of the locations I have seen used I did not like, or the size of the fitting being too small to be very effective.
After spending some time looking a block over, and looking at an assembled engine. I believe I found one of the better spots to install a block vent.

If you have not read this thread.
http://www.dsmtuners.com/forums/cyl...ook-4g63-pcv-system-engine-internal-view.html
You should do so, so you will have a better understanding of why I chose the location I did.

Since there is a factory vent from block to head, tapping into this spot makes the most sense to me. It is on the down side rotation of the crank, and is decently covered and high enough in the block not having to worry about oil slosh or oil return from the head. Also this should pull from the head as well as the block.

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Also looking at an assembled engine, this vent looks to clear the starter and the intake support bracket.

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I chose to use a 1/2npt 45* fitting with a 5/8 hose barb. This should give plenty of cross section and make an effective vent. The ID of the fitting is .530 The reason for a 45* instead of a 90* is so there will be less of a flow restriction through the fitting.

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I scribed a simple circle for the location, then did a center punch dot

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It is a basic drill and tap install.
For a ½ npt the drill size used is 23/32

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Then tap a few thread, care needs to be used since this is a thin cast area.

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Test fit the vent fitting and tap until the proper angle for the hose fittings face the desired angle.

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Try not to extend the threaded portion of the fitting into the factory vent passage.

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[Kirkamus]

must say and sorry for spam but I rank you among the best knowledge base people on engine rebuild/machine workers <3 the work

 

[AllanL]

sorry for being lazy to search...

...but please let us know the purpose of such a vent?

thanks!

 

[1qkfwd]

Better crankcase ventilation which our engines lack.

That spot looks good since it'll allow pressure out and not fight with oil drain back.

You need to really get creative and see how we can improve drain back. Then we would be set.

 

[AllanL]

here it is:

http://www.dsmtuners.com/forums/cyl...ook-4g63-pcv-system-engine-internal-view.html

 

[nitrouskris]

Again another great write up

 

[turbotalon1g]

How many miles on this setup?

 

[LandSpeed-DSM]

Better crankcase ventilation which our engines lack.

That spot looks good since it'll allow pressure out and not fight with oil drain back.

You need to really get creative and see how we can improve drain back. Then we would be set.

Agreed, that is a good spot! I have to think that 1/2" or -8 for the entire crankcase may not be enough though, anything better than none of course!

Anything that keeps blow-by out of the oil return galleys will improve drain back. Simultaneously venting the crankcase and the head is really the only way.

I've begun to believe that only improving flow out the valve cover may actually make things worse, as far as returning oil is concerned. Because the oil now has to fight the same volume of blow-by gas, but with a greater pressure differential between the block and head.

Another spot I am looking to try out next spring is the front balance shaft hole, with a -12. Obviously this is only an option on BSE engines. Both of these along with the two -10s coming out of my VC, with vacuum supplied by the -12 ahead of my turbo should do the job fairly well for a non-drysump setup.

 

[BogusSVO]

LS-D, Glad you like the spot I picked! I stood in the fittings isle looking at both the 1/2 npt and the 3/4 npt fittings.

I bet you know the thread that led me to look into this mod.

http://www.dsmtuners.com/forums/newbie-forum/471722-pvc-port-4g63-block.html

I will say to anyone who wants to do this mod, the engine must be fully apart. I would not even think about doing this "In car" even with the grease method on the drill bit and tap. To me there is just to much risk of cast iron chips to end up in the oil pan.


This thread will walk you through the vent system inside the engine.

http://www.dsmtuners.com/forums/cyl...ook-4g63-pcv-system-engine-internal-view.html

 

[LandSpeed-DSM]

I bet you know the thread that led me to look into this mod.

I do, yes.

So, in your opinion what is the best way to clean the casting flaws out?

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I was going to run a long drill bit and then a rasp through on a block I'm prepping for when my 6-bolt rod/NPR piston motor finally succumbs to the HX52.

 

[gofer]

Is this a good idea on motor with BS's still installed?

Can this be done with the engine assembled?

I think I know the answers to both of these, just a good idea to teach to the lowest common denominator so people aren't getting metal shavings in their oil pan.

 

[BogusSVO]

Gofer, with the spot I chose, It will not matter if the balance shafts are installed or not. This is due to the fact it is not in a BS tunnel.

 

[BogusSVO]

Better crankcase ventilation which our engines lack.

That spot looks good since it'll allow pressure out and not fight with oil drain back.

You need to really get creative and see how we can improve drain back. Then we would be set.

Oh I am tinkering with oil drain back, it is nothing new, just carried over from when I built small blocks.

A 302 on the stand

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So I carried it over to a 4g block

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While I was at it, I did a few..

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How many miles on this setup?

In this location, from me? None.

I do, yes.

So, in your opinion what is the best way to clean the casting flaws out?

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I was going to run a long drill bit and then a rasp through on a block I'm prepping for when my 6-bolt rod/NPR piston motor finally succumbs to the HX52.

I use a die grinder and a long burr

 

[Brandon Mau]

Do you plan on running an inline check valve with this set-up back to the intake or intake manifold. Or just run it to an atmosperic catch can?

 

[1qkfwd]

Im sure that's better than spending hours smoothing the inner block walls with a grinder

Most the problems I have seen are in the head. The casting is crap with the amount of flash that they left behind.

 

[arrowhead]

Is that good all GLYPTAL you are using to paint?

This was very popular with engine builders back in the 60s an 70s, not only helps with oil drainback but it also seals dust and particles when the engine or head has been machine.

The practice fell out of favor in the 80s since some builders claimed the paint was coming off, of course it has probably been improved since then.

I always used it and never have had any problems.

 

[1qkfwd]

Is that good all GLYPTAL you are using to paint?

This was very popular with engine builders back in the 60s an 70s, not only helps with oil drainback but it also seals dust and particles when the engine or head has been machine.

The practice fell out of favor in the 80s since some builders claimed the paint was coming off, of course it has probably been improved since then.

I always used it and never have had any problems.

Im sure its like any paint procedure, prep is everything.

 

[BogusSVO]

Do you plan on running an inline check valve with this set-up back to the intake or intake manifold. Or just run it to an atmosperic catch can?

I got you to outside the block, How you choose to put it to use will be your decision.

I saw where there was some debate on how to vent the block, so this is my .02 cents on the subject.

Im sure that's better than spending hours smoothing the inner block walls with a grinder

Most the problems I have seen are in the head. The casting is crap with the amount of flash that they left behind.

Yeah the head has a good amount of flashing that needs to be dealt with, even in the most stock builds.

Is that good all GLYPTAL you are using to paint?

This was very popular with engine builders back in the 60s an 70s, not only helps with oil drainback but it also seals dust and particles when the engine or head has been machine.

The practice fell out of favor in the 80s since some builders claimed the paint was coming off, of course it has probably been improved since then.

I always used it and never have had any problems.

About the same stuff, I have been using it for years, I have not had an issue with it. Even after it has been through a oven, then hit with an airless shot blaster.

Im sure its like any paint procedure, prep is everything.

Yes, that is true. The block has to be sooooo clean to get this stuff to stick and stay there. any amount of oil mist under it and it will flake off.

 

[bastarddsm]

User MarkL has a similar setup to this. He says he gets about a pint of oil in the catch can after a pass.

 

[Kapok6]

Bogus, instead of using this as a vent, what if you installed the other end of this vent to a vacuum pump?

Thoughts?

 

[YoYo_4G63]

Amazing! where the hose fitting goes connected to? catchcan?

 

[turbotalon1g]

User MarkL has a similar setup to this. He says he gets about a pint of oil in the catch can after a pass.

Mark L has a -16 from the head, not even close to the same setup.

 

[LandSpeed-DSM]

Mark L has a -16 from the head, not even close to the same setup.

If it's what I think you are referring to.. the -16 is an external oil return, not explicitly part of his PCV in the way this sort of block vent is.

 

[bastarddsm]

it is a -16 in the head. However it goes right to the same set of drain-backs, and if you look closely, that's not even a drain-back in the head, it's just a crankcase vent. It's the same thing son.

 

[LandSpeed-DSM]

Which brings me back to one of my earlier thoughts.. so with this external drain we've increased the total cross section allowing oil to drain back, but this has also made it easier for all that blow-by to fight the falling oil to try and escape the crank case to the VC vents.

Having a divorced crank vent like this one that Dale has installed, even one that goes to a can that also connects to the VC vents, would be better than just VC vents. Additional external oil return or not.